, 1887-06-16
A GREAT BRIDGE.
JOEL BENTON WRITES OF A RAIL-
ROAD ENTERPRISE.
Tho Great Structure Now building over
the uudson-A Pleasant Visit to an Inn
portant Engineering Work - How the
Undertaking Is Going Forward.
Especial Correspondence.l


Undertaking Is Going Forward.
Especial Correspondence
New York, May 25.
Few people are very distinctly impressed,
imagine, with the stupendous work that Is
now going OH at Poughkeepse with reference
to railroad crossing over the Hudson river.
That q project to bridge the river at that city
has been frequently talked of almost every
body knows. The opposition to 1t, which al
ways happens when any bridge endeavors to
cross any navigable stream, has done more
than anything to call 1t to recent attention; !;
but even now the magnitude of the scheme Is
hardly realized by the general public. When
1t is remembered, however, that the distance
from shore to shore at that point is 1904
feet, that the approaches on the Poughkeep-
sic side "consist OF q viaduct of 5000 feet In
length" while OH the west side the approaches
add 1000 feet more-making in all one and
onehalf miles almost-it will be seen that the
bridge is to take rank as one of the greatest
structures Of the kind In the world. One
bridge only, it is said, will be longer, and
that is the bridge over the Firth Of Forth in
Great Britain, which is In progress, but
which is not yet built.
A few days since, on the invitation of Mr..
j. ID. Platt, editor of The Poughkeepsie Daily
Eagle, Joined company of $50, who, avail.
ing themselves OF the steamboat g. s. Has
brouck and one of the pleasantest Of May
days, made free and easy excursion around
the piers and cribs Of the bridge and for some
distance above and below the bridge
site. The activity of tho men engaged In
the construction Of this great work was
thus easily seen. About 600 are now
employed on the spot, which force is soon to
be increased one-third, until 1000 are at
oNo md III, ekA,xo Nha ,cs>s. u,,I
steel which is to go into it.
The promoters Of this bridge have already
gone through with quite history in its behalf.
The company was organized first In legal
way in 1871; and the amended act i'm 1872
permitted the placing Of four piers in the
river, "at distances of not less than 500 feet
apart" In 1873 the work was begun, but the
financial panic which soon followed put an
early quietus upon 1t. Several years later it
was taken up again, when other difficulties
called it to halt. Last year, however, new
and extensive capital was enlisted; and it is
under the impetus Of this accession that the
structure is going so rapidly up. Unless the
charter is extended-though it Is expected
this favor will be shown-the whole work
must be ready for use by Jan. 1, 1897. Hence
the present tumultuous hurry and rush Of the
builders seen from either shore.
The present situation is this: The shore
piers, consisting each one of three smaller
piers, are built up from the rock to height
OF forty-five feet above high water" The
river piers ito be carried down to a depth of
from 125 to 1856 feet below the surface" are all
under way. In doing this part Of the work
open cassons Of timber are built 40 feet wide
by 100 feet long, weighted by having pockets
filed with concrete, and sunk by dredging
through the open spaces, which are twelve
in number, in each caisson." This is a differ.
ent method from that used In the BROOKLYN
and ST. Louis bridges; and, while it
is more effective, it Is said not TO
involve the danger and expense which
the pneumatic caissons DO. "As the caissons
sink they are built up by additions from the
top, so that when the lower edges rest upon
the solid substratum underlying the mud and
silt at the bottom Of the river the top will be
about twenty feet below the surface. The
open spaces are then filled with concrete, the
top leveled and a solid platform laid upon it,
and then masonry built on this" The piers,
when completed, will have their length of
eighty feet parallel with tine river. They
will be twenty-five feet wide, and will stand
thirty feet above the surface.
The pier farthest west in the river was
nearly completed years ago. The caisson for
the one next to it is done, and "the work of
dredging is going on. 1t is nearly down to
its final position, the top being already sew
eral feet above the surface" The third cais-
son is placed and is being forced down, and
caisson No. 4 is about completed. The piles
of timber and the car loads not vet thrown
Off on the west shore make an impressive
sight.
Although the bridge, properly so called, Is
to be OF steel, the false work and the wood
sunken make heavy inroads on the forest
"The massive substructures will contain
alone about "12 100000 feet OF timber.n To
this add 10000 cubic yards Of concrete and
10000 yards Of masonry" as additions to the
iron and steel components. From the various
piers steel towers POO feet high will be erected.
The height OF the under side of the trussss
above the water will be 1870 feet There will
be two rectangular steel truss spans, each Of
525 feet and 80 feet high. The three remain.
ing spans are cantilevers, the cantilever arms
being 160 feet each, and the connecting trusses
2l2 feet. The height Of the connecting trusses
will be 1852 feet from the water surface, and
the height Of the rail on top 2l2 feet. The
cantilevers extending from the river piers
will be counterbalanced by the rectangular
trusses, and those on the shore pieces by in
shore arms, each 200 feet long, attached to
the anchorages. / have not myself, OF
course, made these measurements, but Mr..
Platt, who made 1t possible to see the work in
iDs pIoSicso iIoui eNeIJ PoHlt VI tlbW, klnuIy
furnished the statistics. should have said,
however, before finishing with figures, that
the viaducts are to be Of iron, and that "about
1900 tons Of steel and over 6,cOO tons of
iron" are to 60 into the structure.
The bridge is building to connect the coal
fields and the west more closely with New
England, and to make freight exp lses
cheaper by carrying it over the Hudson with
out rehandling. 1t will have double rail
way track, and will be capable OF holding
with entire safety two continuous trains OF
eighty-five ton locomotives, covering the
whole length of both tracks, the ultimate
strength of materials being equal to five times
this strain"
1t is a problem even in Poughkeepsia as to
what effect the bridge may have upon the
growth of that city. But the general supposl-
tion is that it will be favorable. 1t is claimed
thnt as the bridge will lnnl,e Ponnhl,ennsie